Substituted Silacyclopropane Precursors And Their Use For The Deposition Of Silicon-Containing Films

ABSTRACT

Provided are silacyclopropane-based compounds and methods of making the same. Also provided are methods of using said compounds in film deposition processes to deposit films comprising silicon. Certain methods comprise exposing a substrate surface to a silacyclopropane-based precursor and a co-reagent in various combinations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/914,199, filed Dec. 10, 2013, the entire disclosure of which ishereby incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates generally to methods of depositing thinfilms. In particular, the disclosure relates to processes for thedeposition of films comprising silicon.

BACKGROUND

Deposition of thin films on a substrate surface is an important processin a variety of industries including semiconductor processing, diffusionbarrier coatings and dielectrics for magnetic read/write heads. In thesemiconductor industry, in particular, miniaturization requires atomiclevel control of thin film deposition to produce conformal coatings onhigh aspect structures. One method for deposition of thin films withcontrol and conformal deposition is atomic layer deposition (ALD), whichemploys sequential, surface reactions to form layers of precisethickness. Most ALD processes are based on binary reaction sequenceswhich deposit a binary compound film. Because the surface reactions aresequential, the two gas phase reactants are not in contact, and possiblegas phase reactions that may form and deposit particles are limited.Another method for deposition of films is chemical vapor deposition, inwhich two or more reagents are co-flowed to deposit a film over asubstrate.

Silicon is a very important component in semiconductor processing.Currently no process exists for the deposition of silicon-containingmaterials (e.g., SiCN, SiN, SiBN, SiON, etc.) at low temperatures (i.e.,less than about 400° C.) without the use of plasma co-reagents. This isbecause most silicon precursors have limited-reactivity towardschemisorption and/or common co-reagents, such as NH₃, O₂, H₂O.Furthermore, even if a silicon precursor has the requisite reactivity,it can be crucial to have quick reactions during half reaction cycles ofALD, or the growth rate will be too low to be practical for commercialapplications. Additionally, while there are known silicon ALD/CVDprecursors that contain halides, these can be problematic, as thehalides can undesirably end up in the deposited film.

Accordingly, there is a need for new chemistries and methodology for thedeposition of silicon-containing films which addresses one or more ofthe problems described above.

SUMMARY

A first aspect of the disclosure pertains to a compound having astructure represented by formula (IIIA-B), (IVA-B) or (VA-B):

wherein each of R₁₋₁₂ is independently hydrogen, or a linear, branchedor cyclic alkyl group with C₁₋₉, and n ranges from 2 to 6.

Another aspect of the disclosure pertains to a method of making thecompounds of the first aspect, the method comprising reacting a compoundhaving a structure represented by formula (VIA):

with a compound having a structure represented by formula (VII):

wherein each R₁₋₂ are independently H, or C₁₋₉ linear, branched orcyclic alkyl group.

A third aspect of the disclosure pertains to a method of depositing asilicon-containing film. In one or more embodiments, method comprisesexposing a substrate surface to a silicon precursor having a structurerepresented by:

wherein each R, R₁ and R₂ are independently a negatively charged groupor a saturated or unsaturated, linear or branched or cyclic group with1-8 atoms selected from carbon and nitrogen, R₃₋₆ are each independentlya saturated or unsaturated, linear or branched or cyclic group with 1-8atoms selected from carbon and nitrogen and n ranges from 0 to 6. Insome embodiments, the method further comprises exposing the substratesurface to a co-reactant to provide a silicon-containing film.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 shows an exemplary chemical mechanism of a method in accordancewith one or more embodiments of the disclosure; and

FIG. 2 shows an exemplary chemical mechanism of a method in accordancewith one or more embodiments of the disclosure.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the disclosure, it isto be understood that the disclosure is not limited to the details ofconstruction or process steps set forth in the following description.The disclosure is capable of other embodiments and of being practiced orbeing carried out in various ways. It is also to be understood that thecomplexes and ligands of the present disclosure may be illustratedherein using structural formulas which have a particularstereochemistry. These illustrations are intended as examples only andare not to be construed as limiting the disclosed structure to anyparticular stereochemistry. Rather, the illustrated structures areintended to encompass all such complexes and ligands having theindicated chemical formula.

It has been discovered that silicon-containing films can be depositedusing certain silicon precursors which are silacyclopropane-based. Oneor more of the embodiments described herein provide for the depositionof a silicon-containing film at relatively low temperatures (e.g., below400° C.) without the need for plasma co-reagents. Silacyclopropane-basedprecursors may be used as-is, or alternatively may decompose to silyleneto deposit silicon. Although silylenes are generally quite reactive andcan be unstable and/or isolatable at room temperature, aspects of thisdisclosure provide for the silylene to be formed in situ (in an ampouleor in the chamber or at the surface) from a stable molecule(silacyclopropane-based molecules). Silylenes are thought to generate insitu by the decomposition of silacyclopropane-based molecules at orabove a heated surface, or within an ampoule which are then used tocreate silicon containing films by ALD or CVD. Silylenes contain a lonepair on the silicon and will be reactive towards any co-reactant gasduring ALD or CVD processes. It is thought that the in situ productionof silylenes at the surface or above the surface will provide reactivesilicon species for relatively fast (and therefore commercially viable)ALD reactions. Additionally, silylenes produced in situ will lead to thethermal deposition of halide-free silicon containing films at lowtemperatures by ALD or CVD, unlike currently used silicon precursorswhich contain halides.

Aspects of the disclosure therefore provide for the use ofsilacyclopropane-based molecules as precursors to low temperaturedeposition of silicon-containing thin films (e.g., SiN, SiCN, SiBN,SiO₂, etc.) with common ALD/CVD co-reactants such as O₂, H₂O and/or NH₃.The co-reactants may also be enhanced by plasma in some embodiments,although it is not necessary.

Compounds

Accordingly, one aspect of the disclosure relates to certain compoundshaving a structure represented by formula (IIIA-B), (IVA-B) or (VA-B):

wherein each of R₁₋₁₂ is independently hydrogen, or a linear, branchedor cyclic alkyl group with C₁₋₉, and n ranges from 2 to 6. In someembodiments, R₃ and R₄ are each hydrogen. In one or more embodiments,wherein R₁ and R₂ are each methyl.

In further embodiments, the compound has a structure represented byformula (IVC):

wherein each R₁₋₂ is independently a linear, branched or cyclic alkylgroup with C₁₋₉.

Another aspect of the disclosure pertains to methods of producing thecompounds described above. Generally, the process comprises reacting acompound having a structure represented by:

with a compound having a structure represented by:

The specific combination will determine which precursors are ultimatelysynthesized. In some embodiments, reacting the compounds of formula(VI-III), (VI-IV), (VI-VA), or (VI-VB) with (VII-IIIA), (VII-IIIB),(VII-IVA), (VII-IVB), or (VII-V) comprises adding the compound offormula (VI-III), (VI-IV), (VI-VA), or (VI-VB) to a solution comprisinglithium and the compound of formula (VII-IIIA), (VII-IIIB), (VII-IVA),(VII-IVB), or (VII-V). Exemplary synthetic schemes 1-3 follow below:

A specific example of precursor preparation is shown in Scheme 4 below:

Compound X can be synthesized according to literature procedure (seee.g., Haaf, M.; Schmedake, T. A.; Paradise, B. J.; West. R. Can. J.Chem. 2000, 1526-1533). The 2,3-dimethylbut-2-ene can be purchased, forexample, from Sigma Aldrich. A 250 mL schlenk flask may be equipped witha stir bar was charged with Li (0.369 g, 0.0531 mol) and 100 mL of drytetrahydrofuran (THF). The mixture can then be cooled to ˜−78° C. in adry ice/isopropanol bath. While stirring, the 2,3-dimethylbut-2-ene(4.47 g, 0.053 mol) may be slowly added to the flask containing the Lidispersion via syringe. A separate schlenk flask equipped with a stirbar can then be charged with compound X (4.77 g, 0.0177 mol) and 50 mLof dry THF. The compound X mixture may then be transferred via cannulato the flask containing the Li/2,3-dimethylbut-2-ene solution. Aftercomplete addition, the reaction mixture is stirred and slowly warmed upto room temperature by removing the dry ice/isopropanol bath. Themixture may be stirred overnight. The next day, stifling can be stoppedto let the salts settle out. Next, the mixture may be filtered through apad of celite via schlenk filtration techniques. The THF and othervolatiles are removed under reduced pressure. This procedure wouldtheoretically give 5 g (0.0177 mol) of Z.

Deposition Methods

Another aspect of the disclosure pertains to methods of depositingsilicon-containing films. Any of the compounds described above, as wellas additional compounds, may be utilized as silicon precursors.Accordingly, in one or more embodiments, the method comprises exposing asubstrate surface to a silicon precursor having a structure representedby:

wherein R and R₁₋₂ are each independently a negatively charged group,R₃₋₄ are each independently saturated or unsaturated, linear or branchedor cyclic group with 1-8 atoms selected from carbon and nitrogen, and nranges from zero to 6. Formula (I) represents a general formula forsilacyclopropane-based precursors. Formula (II) represents a generalformula for silacyclopropane-based precursors containing cycloalkylgroups. In some embodiments, the substrate surface may then be exposedto a co-reactant to provide a silicon-containing film. In one or moreembodiments, R and R₁₋₂ are each independently a 2-electron donorselected from the groups consisting of azido, cyano and isocyano. Insome embodiments, R and R₁₋₂ are each independently saturated orunsaturated, linear or branched or cyclic group with 1-8 atoms selectedfrom carbon and nitrogen, and n ranges from zero to 6. In one or moreembodiments, R and R₁₋₂ are each independently selected from the groupconsisting of an amine, CN, N₃, Cl and NCO.

A “substrate” as used herein, refers to any substrate or materialsurface formed on a substrate upon which film processing is performedduring a fabrication process. For example, a substrate surface on whichprocessing can be performed include materials such as silicon, siliconoxide, strained silicon, silicon on insulator (SOI), carbon dopedsilicon oxides, silicon nitride, doped silicon, germanium, galliumarsenide, glass, sapphire, and any other materials such as metals, metalnitrides, metal alloys, and other conductive materials, depending on theapplication. Substrates include, without limitation, semiconductorwafers. Substrates may be exposed to a pretreatment process to polish,etch, reduce, oxidize, hydroxylate, anneal and/or bake the substratesurface. In addition to film processing directly on the surface of thesubstrate itself, in the present disclosure, any of the film processingsteps disclosed may also be performed on an underlayer formed on thesubstrate as disclosed in more detail below, and the term “substratesurface” is intended to include such underlayer as the contextindicates. Thus for example, where a film/layer or partial film/layerhas been deposited onto a substrate surface, the exposed surface of thenewly deposited film/layer becomes the substrate surface. In one or moreembodiments, the substrate surface is terminated with —OH, —NH₂, or —NHfunctionality.

Co-reagents may be selected depending upon the film ultimately desired.In one or more embodiments, the co-reagent acts as a precursor foradditional atoms. For example, in some embodiments, a film comprisingsilicon oxide (SiO₂) may be deposited using a co-reagent comprising anoxidant. In one or more embodiments, the oxidant comprises gaseousoxygen (O₂), ozone (O₃) or water (H₂O). In other embodiments, filmscomprising silicon nitride (SiN) may be deposited using a co-reagentcomprising a nitrogen precursor. In one or more embodiments, thenitrogen precursor comprises ammonia (NH₃), hydrazine (N₂H₄) or anamine. In other embodiments, a boron precursor may be used to providesilicon boride (SiB) films. In yet other embodiments, a carbon precursormay be used to produce films comprising silicon carbide (SiC). Examplesof suitable carbon precursor include carbon tetrachloride, alkanes, etc.Some co-reagents may act as precursors for more than one atom. In someembodiments, more than one co-reagent is used, wherein each deposits onetype of atom. For example, a film comprising silicon, carbon andnitrogen (SiCN) may be deposited using carbon sources (e.g., alkane) aswell as nitrogen sources (e.g., ammonia, hydrazine, etc.).

Silacyclopropane-based molecules are relatively reactive and can reactexothermically with oxygen, water, alcohols, ammonia, hydrogen sulfide,carbon tetrachloride, or other such compounds at temperatures as low asroom temperature. While not wishing to be bound to any particulartheory, it is thought that the source of the high reactivity is relatedto the high ring strain of the silacyclopropane moiety. Therefore, it isexpected that silacyclopropane-based precursors will react at elevatedtemperatures with oxygen, water, alcohols, ammonia, hydrogen sulfide, orcarbon tetrachloride species to form silicon-based films deposited byALD or CVD.

The following Equation 1 shows a common decomposition pathway forsilacyclopropane-based molecules (1):

The following Equation 2 shows a proposed decomposition pathway of asilacyclopropane-based complex containing the1,4-di-tert-butyl-diaza-2-enyl-ligand (5):

The following Equation 3 shows the known decomposition pathway ofhexamethylsilirane (7).

Silacyclopropane-based molecules decompose at temperatures of greaterthan about 50° C. to form silylene and the corresponding alkene (4)(Equation 1) from which the silylenes can be used in an ALD/CVD reactorto create silicon containing films at low temperatures, free of halides.In one or more embodiments, it is also possible to tune the propertiesof the molecules by introducing various R groups or cyclic rings to thesilacyclopropane. This can increase or decrease the overall reactivityof the silacyclopropane-based molecule and serve to increase or decreasethe temperature at which the silylene is produced from thesilacyclopropane-based precursor. The R substituents can also influencethe stability of the silylenes that are produced in situ and theproperties of the resulting alkene. For instance, during thedecomposition of a silacyclopropane-based complex containing the1,4-di-tert-butyl-diaza-2-enyl ligand (5) the formation of the stablesilylene 1,3-di-tert-2,3-dihydro-1H-1,3-diazasilol-2-ylidene (6) wouldbe expected (Equation 2). This silylene is stable in the solid state upto 220° C. It has been reported that heating hexamethylsilirane (7)between 65-70° C. results in dimethylsilylene (8) and2,3-dimethyl-2-butene (9) (equation 2). Dimethylsilylene is veryunstable and can only be detected in the gas phase. These examplesdemonstrate the versatility achieved by changing the R groups.

In one or more embodiments, the method comprises an atomic layerdeposition (ALD) process. As used herein, “atomic layer deposition”refers to a process in which a substrate surface is exposed to alternateor sequential flows of a precursor and/or reagent. That is, theprecursor and/or reagents may be flowed and/or exposed to the substratesurface sequentially or substantially sequentially. As used herein“substantially sequentially” refers to where the flows of the precursorand/or reagents do not overlap for a majority of the flow.

Therefore, in one exemplary embodiment, a silacyclopropane-based siliconprecursor may be vaporized into an ALD chamber where the molecule canreact with a surface group (OH, NH₂, etc) to provide a silyl terminatedsurface, followed by an inert purge. Then, the silyl terminated surfacemay be exposed to a co-reagent such as O₂, H₂O, NH₃, or plasma activatedspecies (O₂, H₂O, NH₃, etc.) which would further react with the silylspecies to form a layer of silicon-containing material. Repeating thiscycle should afford films with precise thickness control. In anexemplary embodiment, the substrate temperature can be about 50-400° C.

FIG. 1 shows a possible mechanism of an example of self-limited filmgrowth by an ALD process consisting of a silacyclopropane siliconprecursor and ammonia co-reagent during one ALD cycle. The process inthe figure begins with an amino (NH₂) terminated silicon surface that isheated (a). Next, the silacyclopropane-based precursor is introduced tothe heated surface and reacts with the available NH₂ surface sites toform silicon-nitrogen bonds with the subsequent elimination of an alkane(b). After an inert gas purge, ammonia gas is introduced to the surfacewhich reacts with the R groups to terminate the surface with aminogroups and the free alkane is subsequently released (c) followed by aninert purge. Finally, the surface is NH2 terminated and ready forproceeding ALD cycles.

In one or more similar embodiments, the reactive species at the surfaceis the silylene. The silacyclopropane-based molecule undergoes thermalself-decomposition at the substrate surface to form a silylene-basedmolecule which than can react with the reactive surface sites. As longas the silylene does not react with itself, then self-limited filmgrowth is thought to occur. An inert purge would follow thesilacyclopropane-based molecule pulse, followed by treatment with aco-reagent gas, which would then react with the chemisorbed siliconspecies at the substrate surface. This will result in the formation of asilicon-containing film. The cycle may then be repeated until thedesired film thickness is achieved. Repeating this cycle would lead tosilicon containing films with precise thickness control. FIG. 2 shows apossible mechanism for self-limited film growth by in-situ production ofthe silylene from the silacyclopropane. In (a), a substrate surface with—NH₂ terminations are provided. In (b), a silicon precursor accordancewith one or more embodiments of the disclosure is flowed in. Theprecursor decomposes to silylene-based molecule, which can react withthe —NH₂ substrate surface terminations. In (c), the silylene-basedmolecule chemisorbs onto the substrate surface. In (d), ammonia is usedas a co-reagent to form silicon nitride. In (e), the substrate surfaceis purged, leaving behind silicon nitride, with available —NH₂terminations for additional deposition cycles.

In some embodiments, silylene is thermally generated in a heated ampouleat temperature of about 30 to 200° C. Then, the evolved silylene couldbe delivered to the deposition chamber for film formation. The silylenecould form a film as described above.

In some embodiments, the method comprises a chemical vapor deposition(CVD) process. As used herein, “chemical vapor deposition” refers to aprocess in which a substrate surface is exposed to precursors and/orco-reagents simultaneous or substantially simultaneously. As usedherein, “substantially simultaneously” refers to either co-flow or wherethere is overlap for a majority of exposures of the precursors. In oneor more embodiments, any co-reagent is added with any one or more of thereactants.

Therefore, in one or more embodiments, the silacyclopropane-basedmolecule is vaporized into a reaction chamber and the reactant gas isco-flowed to form a silicon containing film. In some embodiments, thereactive species in the chamber and at the substrate surface issilylene. The silylene is generated from the silacyclopropane-basedmolecule that would decompose in the chamber at or above the substrate.The silylene species may then react with a co-reagent by chemical vapordeposition to form a silicon containing film. In some embodiments, thesubstrate temperatures may range from about 50, 70, 100 to about 150,200, 250, 300, 350, 400 or 500° C.

Again, in some embodiments, silylene is thermally generated in a heatedampoule at temperature of, for example, about 30 to 200° C. Then, theevolved silylene could be delivered to the deposition chamber for filmformation. The silylene could form a film as described above.

Purges may be used after first, second and/or third precursors areflowed into the deposition chamber. That is, the substrate and chambermay be exposed to a purge step after stopping the flow of the givenprecursor gas. A purge gas may be administered into the processingchamber with a flow rate within a range from about 10 sccm to about2,000 sccm, for example, from about 50 sccm to about 1,000 sccm, and ina specific example, from about 100 sccm to about 500 sccm, for example,about 200 sccm. The purge step removes any excess precursor, byproductsand other contaminants within the processing chamber. The purge step maybe conducted for a time period within a range from about 0.1 seconds toabout 8 seconds, for example, from about 1 second to about 5 seconds,and in a specific example, from about 4 seconds. The carrier gas, thepurge gas, the deposition gas, or other process gas may containnitrogen, hydrogen, argon, neon, helium, or combinations thereof. In oneexample, the carrier gas comprises nitrogen.

The reaction conditions for the reaction will be selected based on theproperties of the film precursors and substrate surface, and anyco-reagents. The deposition may be carried out at atmospheric pressure,but may also be carried out at reduced pressure. The vapor pressure ofany co-reagents should be low enough to be practical in suchapplications. The substrate temperature should be low enough to keep thebonds of the substrate surface intact and to prevent thermaldecomposition of gaseous reactants. However, the substrate temperatureshould also be high enough to keep the film precursors in the gaseousphase and to provide sufficient energy for surface reactions. Thespecific temperature depends on the specific substrate, film precursors,and catalyst used and pressure. The properties of the specificsubstrate, film precursors, and catalyst may be evaluated using methodsknown in the art, allowing selection of appropriate temperature andpressure for the reaction.

In one or more embodiments, the deposition is carried out at atemperature from about to 50 or 75 to about 500, 450, 400, 350, 300,250, 200, 150, 125, or 100° C. In some embodiments, the deposition iscarried out at a temperature in the range of about 50 to about 500° C.,70 to about 100° C., about 70 to about 125° C. or about 70 to about 125°C.

In some embodiments, one or more layers may be formed during a plasmaenhanced atomic layer deposition (PEALD) process, although therelatively high reactivity of the precursors described herein generallydo not require the assistance of a plasma-based process. In someprocesses, the use of plasma provides sufficient energy to promote aspecies into the excited state where surface reactions become favorableand likely. Introducing the plasma into the process can be continuous orpulsed. In some embodiments, sequential pulses of precursors (orreactive gases) and plasma are used to process a layer. In someembodiments, the reagents may be ionized either locally (i.e., withinthe processing area) or remotely (i.e., outside the processing area). Insome embodiments, remote ionization can occur upstream of the depositionchamber such that ions or other energetic or light emitting species arenot in direct contact with the depositing film. In some PEALD processes,the plasma is generated external from the processing chamber, such as bya remote plasma generator system. The plasma may be generated via anysuitable plasma generation process or technique known to those skilledin the art. For example, plasma may be generated by one or more of amicrowave (MW) frequency generator or a radio frequency (RF) generator.The frequency of the plasma may be tuned depending on the specificreactive species being used. Suitable frequencies include, but are notlimited to, 2 MHz, 13.56 MHz, 40 MHz, 60 MHz and 100 MHz. Althoughplasmas may be used during the deposition processes disclosed herein, itshould be noted that plasmas may not be required. Indeed, otherembodiments relate to deposition processes under very mild conditionswithout a plasma.

According to one or more embodiments, the substrate is subjected toprocessing prior to and/or after forming the layer. This processing canbe performed in the same chamber or in one or more separate processingchambers. In some embodiments, the substrate is moved from the firstchamber to a separate, second chamber for further processing. Thesubstrate can be moved directly from the first chamber to the separateprocessing chamber, or it can be moved from the first chamber to one ormore transfer chambers, and then moved to the desired separateprocessing chamber. Accordingly, the processing apparatus may comprisemultiple chambers in communication with a transfer station. An apparatusof this sort may be referred to as a “cluster tool” or “clusteredsystem”, and the like.

Generally, a cluster tool is a modular system comprising multiplechambers which perform various functions including substratecenter-finding and orientation, degassing, annealing, deposition and/oretching. According to one or more embodiments, a cluster tool includesat least a first chamber and a central transfer chamber. The centraltransfer chamber may house a robot that can shuttle substrates betweenand among processing chambers and load lock chambers. The transferchamber is typically maintained at a vacuum condition and provides anintermediate stage for shuttling substrates from one chamber to anotherand/or to a load lock chamber positioned at a front end of the clustertool. Two well-known cluster tools which may be adapted for the presentdisclosure are the Centura® and the Endura®, both available from AppliedMaterials, Inc., of Santa Clara, Calif. The details of one suchstaged-vacuum substrate processing apparatus are disclosed in U.S. Pat.No. 5,186,718, entitled “Staged-Vacuum Wafer Processing Apparatus andMethod,” Tepman et al., issued on Feb. 16, 1993. However, the exactarrangement and combination of chambers may be altered for purposes ofperforming specific steps of a process as described herein. Otherprocessing chambers which may be used include, but are not limited to,cyclical layer deposition (CLD), atomic layer deposition (ALD), chemicalvapor deposition (CVD), physical vapor deposition (PVD), etch,pre-clean, chemical clean, thermal treatment such as RTP, plasmanitridation, degas, orientation, hydroxylation and other substrateprocesses. By carrying out processes in a chamber on a cluster tool,surface contamination of the substrate with atmospheric impurities canbe avoided without oxidation prior to depositing a subsequent film.

According to one or more embodiments, the substrate is continuouslyunder vacuum or “load lock” conditions, and is not exposed to ambientair when being moved from one chamber to the next. The transfer chambersare thus under vacuum and are “pumped down” under vacuum pressure. Inertgases may be present in the processing chambers or the transferchambers. In some embodiments, an inert gas is used as a purge gas toremove some or all of the reactants after forming the layer on thesurface of the substrate. According to one or more embodiments, a purgegas is injected at the exit of the deposition chamber to preventreactants from moving from the deposition chamber to the transferchamber and/or additional processing chamber. Thus, the flow of inertgas forms a curtain at the exit of the chamber.

The substrate can be processed in single substrate deposition chambers,where a single substrate is loaded, processed and unloaded beforeanother substrate is processed. The substrate can also be processed in acontinuous manner, like a conveyer system, in which multiple substrateare individually loaded into a first part of the chamber, move throughthe chamber and are unloaded from a second part of the chamber. Theshape of the chamber and associated conveyer system can form a straightpath or curved path. Additionally, the processing chamber may be acarousel in which multiple substrates are moved about a central axis andare exposed to deposition, etch, annealing, cleaning, etc. processesthroughout the carousel path.

During processing, the substrate can be heated or cooled. Such heatingor cooling can be accomplished by any suitable means including, but notlimited to, changing the temperature of the substrate support andflowing heated or cooled gases to the substrate surface. In someembodiments, the substrate support includes a heater/cooler which can becontrolled to change the substrate temperature conductively. In one ormore embodiments, the gases (either reactive gases or inert gases) beingemployed are heated or cooled to locally change the substratetemperature. In some embodiments, a heater/cooler is positioned withinthe chamber adjacent the substrate surface to convectively change thesubstrate temperature.

The substrate can also be stationary or rotated during processing. Arotating substrate can be rotated continuously or in discreet steps. Forexample, a substrate may be rotated throughout the entire process, orthe substrate can be rotated by a small amount between exposures todifferent reactive or purge gases. Rotating the substrate duringprocessing (either continuously or in steps) may help produce a moreuniform deposition or etch by minimizing the effect of, for example,local variability in gas flow geometries.

In atomic layer deposition type chambers, the substrate can be exposedto the first and second precursors either spatially or temporallyseparated processes. Temporal ALD is a traditional process in which thefirst precursor flows into the chamber to react with the surface. Thefirst precursor is purged from the chamber before flowing the secondprecursor. In spatial ALD, both the first and second precursors aresimultaneously flowed to the chamber but are separated spatially so thatthere is a region between the flows that prevents mixing of theprecursors. In spatial ALD, the substrate must be moved relative to thegas distribution plate, or vice-versa. Use of the terms “expose to asubstrate surface” and “flow” is intended to encompass both processes.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe disclosure. Thus, the appearances of the phrases such as “in one ormore embodiments,” “in certain embodiments,” “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the disclosure.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Although the disclosure herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent disclosure. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present disclosure without departing from the spiritand scope of the disclosure. Thus, it is intended that the presentdisclosure include modifications and variations that are within thescope of the appended claims and their equivalents.

What is claimed is:
 1. A compound having a structure represented byformula (IIIA-B), (IVA-B) or (VA-B):

wherein each of R₁₋₁₂ is independently hydrogen, or a linear, branchedor cyclic alkyl group with C₁₋₉, and n ranges from 2 to
 6. 2. Thecompound of claim 1, wherein R₃ and R₄ are each hydrogen.
 3. Thecompound of claim 1, wherein R₁ and R₂ are each methyl.
 4. The compoundof claim 1, wherein the compound has a structure represented by formula(IVC):

wherein each R₁₋₂ is independently a linear, branched or cyclic alkylgroup with C₁₋₉.
 5. The compound of claim 1, wherein each R₁₋₂ ismethyl.
 6. A method of making the compound of claim 1, the methodcomprising: reacting a compound having a structure represented byformula (VI-III), (VI-IV), (VI-VA) or (VI-VB):

with a compound having a structure represented by:


7. The method of claim 6, wherein reacting the compounds of formula(VI-III), (VI-IV), (VI-VA), or (VI-VB) with (VII-IIIA), (VII-IIIB),(VII-IVA), (VII-IVB), or (VII-V) comprises adding the compound offormula (VI-III), (VI-IV), (VI-VA), or (VI-VB) to a solution comprisinglithium and the compound of formula (VII-IIIA), (VII-IIIB), (VII-IVA),(VII-IVB), or (VII-V).
 8. A method of making the compound of claim 6,wherein the compound having a structure represented by formula (VI)comprises a compound having a structure represented by formula (VIA):

and the compound having the structure represented by formula:

wherein each R₁₋₂ is independently H, or C₁₋₉ linear, branched or cyclicalkyl group.
 9. The method of claim 8, wherein each R₁₋₂ is methyl. 10.A method of depositing a silicon-containing film, the method comprising:a. exposing a substrate surface to a silicon precursor having astructure represented by:

wherein each R, R₁ and R₂ are independently a negatively charged groupor a saturated or unsaturated, linear or branched or cyclic group with1-8 atoms selected from carbon and nitrogen, R₃₋₆ are each independentlya saturated or unsaturated, linear or branched or cyclic group with 1-8atoms selected from carbon and nitrogen and n ranges from 0 to 6; and b.exposing the substrate surface to a co-reactant to provide asilicon-containing film.
 11. The method of claim 10, wherein thesubstrate surface is terminated with —OH, —NH₂, or —NH functionality.12. The method of claim 10, wherein the co-reactant is selected from thegroup consisting of an oxidant, and the silicon-containing film furthercomprises oxygen.
 13. The method of claim 12, wherein the oxidant isselected from the group consisting Of O₂, O₃ and H₂O.
 14. The method ofclaim 10, wherein the co-reactant comprises ammonia, hydrazine or anamine, and the silicon-containing film further comprises nitrogen. 15.The method of claim 10, wherein the method is an atomic layer depositionmethod.
 16. The method of claim 15, wherein exposing the substratesurface to the silicon precursor provides silyl terminations at thesubstrate surface, and exposing the substrate surface to a co-reactantcomprises exposing the co-reactant to the silyl terminations.
 17. Themethod of claim 10, wherein the method is a chemical vapor depositionmethod.
 18. The method of claim 17, wherein exposing the substratesurface to the co-reactant and the silicon precursor occurssimultaneously.
 19. The method of claim 10, wherein the siliconprecursor undergoes thermal self-decomposition at the substrate surfaceto form a silylene-based molecule at the substrate surface.
 20. Themethod of claim 10, wherein the silicon precursor is selected from thegroup consisting of:

wherein each of R₁₋₁₂ is each independently H, or C₁₋₉ linear, branchedor cyclic alkyl group, and n ranges from 0 to 6.